Broad overview of engineering of functional nanosystems for skin delivery.

Nanotechnology involves the engineering of functional systems at nanoscale and it can be described as a collection of methods and techniques for processing materials to create products with special physicochemical properties. The rapid developments in nanotechnology have allowed the incorporation of therapeutic agents, actives for cosmetic, sensing agents into nanoparticles, for detection, prevention, and treatment of skin diseases. Nanoparticles promote the increase of penetration of drugs and many cosmetic chemicals across the skin. Nanoparticles offer many advantages as carrier systems since they can improve the solubility of poorly water-soluble drugs or actives such as phytocompounds, permeate the skin through different mechanisms, modify drug or actives pharmacokinetic and ultimately, improve their bioavailability. In this review, we discuss the recent advances of different types of nanoparticles for skin delivery over a period of 40 years. This review emphasizes approaches to overcome the drawbacks and limitations associated with the conventional systems and the advances and application that are poised to further enhance the efficacy of topical formulations with nanoparticles, offering the possibility of simplified dosing regimen that may improve treatment outcomes using these novel delivery nanosystems.